Why does my basement sink gurgle when the kitchen sink drains?
Air is being pulled through the basement sink trap because the drainage system lacks proper ventilation or has a blockage. This pressure imbalance creates loud bubbling noises and disrupts normal plumbing flow.
What the numbers show
Counted from the threads quoted below. How we count
- The most recent one is from October 2026.
- This comes up 14.1× more often in r/Plumbing than across the site as a whole.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
Found another way around this?
Share your steps and trade-offs so fellow engineers don't have to reinvent the wheel. No account required.
- 1Using a sink plunger3 people mentionedDid this help you?
- 2Trying to clear the drain as far as hand can reach2 people mentionedDid this help you?
- 3using boiling water2 people mentionedDid this help you?
- 4Swapping improper fittings like Wye fittings for Tee fittingsDid this help you?
- 5Using an inflatable bladder or plumbing snake to clear potential clogs in the main drain lineDid this help you?
- 6Pouring boiling water down the drainDid this help you?
- 7reaching as far as hand can reachDid this help you?
- 8trying baking soda and white vinegarDid this help you?
- 9Cleaning out the P-trapDid this help you?
- 10Loosening the assembly to adjust the slope and ensure a downhill flow toward the wallDid this help you?
- 11Tightening the existing copper nutDid this help you?
- 12Removing the drain, scraping off old putty, applying fresh plumber's putty, and reassemblingDid this help you?
- 13Searching YouTube for instructional videosDid this help you?
- 14Applying plumbers putty above and below the rubber washerDid this help you?
- 15Using pipe dope or silicone grease on the gasket and threadsDid this help you?
- 16Tightening the locknut further using Channel Locks or a screwdriver and malletDid this help you?
- 17Replacing the cheap plastic drain with a metal tailpiece and nutDid this help you?
- 18Using accordion drains and slip couplings as improvised trapsDid this help you?
- 19Drawing diagrams to ask for configuration feedback onlineDid this help you?
In their words
Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.
“Currently, after plunging and using boiling water, the sink will now drain but VERY slowly (over 10+ hours I'd say for a small amount of water).”source ↗
“One we didn’t notice is a small leak under the bathroom sink in this area. I tried tightening the copper nut but it’s very tight already as is. Before I start messing with things, is this an easy fix?”source ↗
“This kind of thing isn’t my strength so I don’t want to start taking things apart.”source ↗
“A week ago, I vomited in my bathroom sink in my apartment. Now, I've been out of a sink for a week even after clearing the drain as far as my hand could reach, and I used a sink plunger.”source ↗
“Currently, after plunging and using boiling water, the sink will now drain but VERY slowly (over 10+ hours I'd say for a small amount of water).”source ↗
“Not having a bathroom sink has significant put part of my daily personal hygiene on hold and I want my bathroom back.”source ↗
“Had the same issue. Putty above and below the rubber washer fixed it.”source ↗
“Every time I turn on the kitchen sink and it drains, it causes a loud bubbling sound that comes out of the basement sink.”source ↗
“I assume it’s a ventilation issue but I do not know how to fix it.”source ↗
“Currently, after plunging and using boiling water, the sink will now drain but VERY slowly (over 10+ hours I'd say for a small amount of water).”source ↗
“Recently replaced this copper part now water doesn’t go down (it does but very very very slowly). Did I do something wrong?”source ↗
“Yeah, the original setup had the same parts and worked. The copper piece bursted, so I removed them and took them to a hardware store and bought the same pieces. The guy even cut them for me to be of the same size. I installed everything, and now the water is slow.”source ↗
“Water is leaking from the red arrow. We put plumbers putty under the drain flange and tightened the locknut but the sink doesn’t really look like what I see online for standard assembly?”source ↗
“We just bought this house. I do want to replace the whole sink and vanity at some point but for right this second I just want it to stop leaking”source ↗
“We also were just tightening it by hand so I was wondering if it’s just not tight enough.”source ↗
“ignore the white lines, idek what they are.”source ↗
“Is the first one bad or is it fine, and is the drawing better or is it dumb(and does it make sense and is it possible). other ideas welcome i dont have better pics 🙏”source ↗
“Or are the slip couplings put together attached to the accordion drain supposed to be your trap?”source ↗
Where this came up
People with this problem also raised
- 30Why does my sink drain keep clogging up?
- 4Why do my pipes knock when multiple faucets are running?
- 21Why is a newly installed sink drain leaking above the trap?
- 22How to fix an off-center toilet drain during a remodel
- 27Can you fix a cracked or broken kitchen sink yourself?
- 3Why does my shower make a humming noise?